1. Field of the Invention
The present invention relates to a dental impression paper tray used for a purpose of an impression-taking in a mouth in a dental treatment.
2. Description of the Related Art
When prostheses such as dentures and the like are made in a dental treatment, an impression in the mouth of a patient is collected by use of an impression tray.
Conventional dental impression trays are generally made of metal or plastic. Since dental impression trays are expensive, they are cleaned after having been used so that they can be used repeatedly.
However, when impression trays are used repeatedly, they give a feeling of uneasiness and a sense of uncleanliness to patients because they may be broken or corroded in a cleaning operation as well as there is a problem of infection such as AIDS caused by HIV. Thus, there have been desired disposable impression trays.
To satisfy this desire, there has been developed a disposable impression tray as disclosed in Japanese Patent Laid-open No. HEI 4-317648 (1992). This disposable tray is composed of a thermoplastic resin with reinforced fibers.
Nevertheless, since the conventional disposable dental impression tray contains the resin, when the tray is intended to be disposed by incineration as a generally used waste disposal method, a high thermal energy is needed and further a toxic gas is generated depending upon a type of the resin, reinforced fibers and other additives. As a result, a problem of air pollution arises and causes general personal dentist clinics to find it difficult to dispose the tray by themselves.